Isosceles and Equilateral Triangles

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length and the angles opposite those sides are equal.

Tags

CCSS.4.G.A.2

Front

What is an equilateral triangle?

Back

An equilateral triangle is a triangle in which all three sides are of equal length and all three angles are equal, each measuring 60°.

Tags

CCSS.4.G.A.2

Front

What is the sum of the interior angles of a triangle?

Back

The sum of the interior angles of a triangle is always 180°.

Tags

CCSS.8.G.A.5

Front

If two angles of a triangle are equal, what can be said about the triangle?

Back

The triangle is isosceles.

Tags

CCSS.2.G.A.1

Front

In an isosceles triangle, if the base angles are 40°, what is the measure of the vertex angle?

Back

The vertex angle measures 100°.

Tags

CCSS.8.G.A.5

Front

What is the relationship between the angles in an equilateral triangle?

Back

All angles in an equilateral triangle are equal, each measuring 60°.

Tags

CCSS.HSG.CO.C.11

Front

How do you find the measure of an unknown angle in a triangle?

Back

To find an unknown angle, subtract the sum of the known angles from 180°.

Tags

CCSS.8.G.A.5

Front

If one angle of an isosceles triangle measures 88°, what are the measures of the other two angles?

Back

The other two angles each measure 46°.

Tags

CCSS.8.G.A.5

Front

What is the formula for the area of a triangle?

Back

The area of a triangle is given by the formula: Area = 1/2 * base * height.

Tags

CCSS.6.G.A.1

Front

In an isosceles triangle, if the equal sides measure 10 cm and the base measures 8 cm, how can you find the height?

Back

You can use the Pythagorean theorem to find the height by splitting the triangle into two right triangles.

Tags

CCSS.8.G.B.8